Full vulcanized thermoplastic elastomer is a new material developed in 1980's and it has characteristic performances of both plastics and rubber, which shows high elasticity of rubber at room temperature and can be also plasticizing-shaped at high temperature. The strength, elasticity, heat resistance and compressive permanent deformation resistance of full vulcanized thermoplastic elastomer are much higher than those of non-crosslinked thermoplastic elastomer, and at the same time its chemistry resistance and processing stability are significantly improved, and the blending ratio of rubber and plastics can vary in a broader range such that the material performance can adjust largely and thus its application ranges are very broad. In traditional technology, full vulcanized thermoplastic elastomer is prepared by dynamic vulcanization of thermoplastic elastomer and rigid thermoplastic plastics under certain condition.
China patent CN1184265C of the applicant (application date: Jun. 15, 2001, priority date: Jun. 15, 2000, Patent number ZL01801655.3) provides a full vulcanized thermoplastic elastomer having controllable particle diameter of rubber phase and sphere-like shape and its preparation method. Such full vulcanized thermoplastic elastomer is prepared through common blending method for processing rubber and plastics by blending and granulating full vulcanized powdered rubber and plastics via rubber plastics blending equipment. The weight ratio of full vulcanized powdered rubber to plastics is in the range from 30:70 to 75:25, preferably 50:50-75:25, wherein rubber component is rubber particle having crosslinking structure and its mean particle diameter is in the range from 0.02 to 1 μm, preferably 0.05 to 0.5 μm, more preferably 0.05 to 0.2 μm. Such rubber particle has gel content of 60 wt % or greater which can be selected from the full vulcanized powdered rubber prepared from international patent application WO01/40356 filed on Sep. 18, 2000 by this applicant including at least one full vulcanized powdered rubber selected from the group consisting of full vulcanized powdered natural rubber, full vulcanized powdered styrene butadiene rubber, full vulcanized powdered carboxylic styrene butadiene rubber, full vulcanized powdered nitrile rubber, full vulcanized powdered carboxylic nitrile rubber, full vulcanized powdered polybutadiene rubber, full vulcanized powdered chloroprene rubber, full vulcanized powdered silicone rubber, full vulcanized powdered acrylate rubber, full vulcanized powdered butadiene-styrene-vinylpyridine rubber, full vulcanized powdered isoprene rubber, full vulcanized powdered butyl rubber, full vulcanized powdered polysulfide rubber, full vulcanized powdered acrylate-butadiene rubber, full vulcanized powdered polyurethane rubber and full vulcanized powdered fluorubber etc, and the plastics of the full vulcanized thermoplastic elastomer comprise at least one selected from the group consisting of polypropylene, polyethylene, polyamide polyvinylchloride, polyurethane, polyester, polycarbonate, polyformaldehyde, polystyrene, polyphenylene sulfide, polyimide, and polysulfone etc.
In addition, China patent CN1381524A of the applicant (application date: Apr. 18, 2001, Patent number ZL01110734.0) provides a full vulcanized polyolefin thermoplastic elastomer and its preparation method. Such full vulcanized polyolefin thermoplastic elastomer is prepared by blending components including polyolefin plastics and rubber, wherein the weight ratio of rubber component to polyolefin plastics is in the range from 30:70 to 75:25, preferably 50:50 to 75:25, and rubber component is rubber particle having crosslinking structure. Such rubber particle is preferably homogenous phase structure and its mean particle diameter is in the range from 0.02 to 1 μm, preferably 0.05 to 0.5 μm, more preferably 0.05 to 0.3 μm. Such rubber particle has gel content of 60 wt % or greater, preferably 80 wt % or greater which can be selected from the full vulcanized powdered rubber prepared from international patent application WO01/40356 (priority date: Dec. 3, 1999) filed on Sep. 18, 2000 by this applicant including at least one full vulcanized powdered rubber selected from the group consisting of full vulcanized powdered natural rubber, full vulcanized powdered styrene butadiene rubber, full vulcanized powdered polybutadiene rubber and full vulcanized powdered silicone rubber etc. Alternatively, such rubber particle can be selected from the crosslinked type powdered rubber prepared from China patent CN1353131A of the applicant (application date: Nov. 3, 2000, Patent number ZL00130386.4) which can comprise at least one of crosslinked type powdered styrene butadiene rubber and crosslinked type powdered polybutadiene rubber etc. The polyolefin plastics of full vulcanized polyolefin thermoplastic elastomer comprises homopolymer, copolymer of polyolefin plastics and blends thereof and preferably at least one of polypropylene, polypropylene copolymer, polyethylene and polyethylene copolymer etc.
The above full vulcanized thermoplastic elastomer was prepared through common blending method for processing rubber and plastics by melt-blending and granulating components including full vulcanized powdered rubber and plastics via rubber plastics blending equipment under common plastics processing temperature.
The full vulcanized thermoplastic elastomers provided by CN11842650 and CN1381524A have good controllable particle diameter and gel content of rubber phase and good mechanic properties compared to the full vulcanized thermoplastic elastomer prepared by traditional dynamic vulcanization method. In particular, they have higher whiteness value and can be easily made into light colorful products, and can be easily dyed and made into other colorful products. At the same time, the preparation methods of full vulcanized thermoplastic elastomers from these patent applications are simple. Contrast to the dynamic vulcanization method, common rubber plastics blending equipment is used without particular equipments, and the process is simple and the processing conditions can be controlled easily, and furthermore, the controllability of rubber phase particle diameter and crosslinking degree are good.
However, the full vulcanized thermoplastic elastomers prepared by CN1184265C and CN1381524A are not conductive, which are not suitable to particular applications requiring conductivity.